Botvinnik said that he learnt most from analyzing of grandmasters. In my blog the Alekhine games Alekhine analyzed. He saw the possibilities very well. His "300 selected games" there is on the net, to play these games is very good studying.

It's all part of the learning curve.  You'll get better the more you do it.  When I first started, I could barely handle 3 games, let alone 6.  And over 10 would've given me fits.  Now I have 15 going on simultaneously!  Is it magic?  No, you just learn how to quickly analyze the position, hopefully remembering what it was that you wanted to accomplish on your last move.  Keep in mind 2 things:

1. Learn from your mistakes.  If you never made any mistakes, you'd never get any better.  Playing under intense circumstances creates opportunities for you to be tested.  If you can make the right moves when you're being pushing to your limits, then you're more likely to play well when less pressured.

2. Positions are more important than flawless play.  Masters have the ability to glance at a board and know immediately what's going on.  This is an ability that is partly innate, but most of us can only achieve it by practice.  Having a large number of games available to study (and call your own) helps you develop your position-recognizing skills.